The English abbreviation and its explanation involved in the present text are as follows.                3G: the 3rd-Generation mobile communication technology;        LTE: the Long Term Evolution system;        GSM: the Global System of Mobile Communication system;        EPC: the Evolved Packet Core;        eNB, eNodeb: the Evolved Node B (the evolved base station);        E-URTAN: the Evolved Universal Terrestrial Radio Access Network;        UE: the User Equipment (the user terminal);        MME: the Mobility Management Entity, which is a core network element related to mainly processing the signaling;        S GW: the Serving Gateway, which is a core network element related to mainly processing the service;        Femto: the Femto cell system, mainly including the Femto base station and the Femto gateway;        HNB: the Home Node B, the Femto base station using the 3G mode;        HeNB: the Home eNB, the Femto base station using the LTE mode;        HeNB GW: the Home eNB Gateway (HeNB gateway);        SCTP: the Stream Control Transmission Protocol;        TAC: the Tracking Area Code;        CSG: the Closed Subscriber Group;        PLMN: the Public Land Mobile Network;        HeMS: the Home eNB management system;        Global eNB ID, the global network eNB identifier;        AP: the Access Point.        
The LTE system is the evolution of the 3rd generation mobile communication system, and the whole LTE system is made up of three parts, the eNB, the EPC and the UE. FIG. 1 shows a network structure chart of a LTE system. The eNB is an evolved base station, the EPC is responsible for the part of the core network, including the MME and the S GW, and the UE is the user terminal, wherein, multiple eNBs at the E-URTAN side access the MME/S-GW through the S1 interface, and every eNB is connected to one another through the X2 interface.
With the continuous extension of the scale of the macro network (the 3G network or the LTE network), the user quantity is increasing constantly, and the requirement on data bandwidth of the user is increased constantly. Because the utilization frequency of the 3G network and the LTE network is higher, and compared with the GSM, the penetrability of its signal is poor, the indoor coverage becomes a difficult point of the network optimization, and the indoor coverage of the 3G network or the LTE network is generally realized by adopting the mode of establishing the indoor distribution system. However, under the existing condition, the indoor distribution system can generally be established only in some hotels, medium-to-high grade communities or public hot places. As to the general residential quarters, limited to various conditions, it is unable to establish the indoor distribution system, so the indoor 3G or LTE signal is very weak or even there is no signal at all, which causes great influence to user experience.
For this reason, a Femto system has already been proposed, that is, the Femto cell system. Its adopted public broadband or operator transmission access is to access the security gateway and the core network of the operator through the Internet, thus providing the wireless signal coverage to the user, which can improve the user experience and is an important technology to make up for the blind points and the hot points of the indoor coverage. About the Femto system, it is mainly made up of the Femto base station and the femto gateway, wherein, the Femto base station is divided into the Femto base station using the 3G standard and the Femto base station HeNB using the LTE standard according to the difference of its adopted wireless technologies.
FIG. 2 shows a network element structure diagram of a Femto system of the LTE standard. The HeNB GW is introduced in the LTE system, and multiple HeNBs are linked to the HeNB GW. First of all, the HeNB GW is one-to-multiple connected to multiple HeNBs through S1 links; secondly, the HeNB GW is further one-to-multiple accessed to multiple MME/S-GWs through S1 links to perform the load sharing and the disaster recovery backup. In addition, the HeNB can also be accessed to the MME/S-GW through the S1 directly. Other network elements of the Femto system of the LTE standard also include the HeMS (not shown in FIG. 2) for configuring the related parameters of the HeNB.
As to the macro network base station eNB, the current protocol (36413) stipulates that the S1 message between the eNB and the MME only supports maximum 256 tracking area codes (TACs), maximum 256 closed subscriber groups (CSGs) and maximum 6 public land mobile networks (PLMNs). Under the situation that the cell number is limited, the maximum values stipulated by the protocol in the macro network eNB system will not generate the problem.
But for the Femto base station HeNB, after introducing the HeNB GW, the HeNB GW is a macro network eNB in the view of the MME. There is only one S1 link between one macro network eNB and a single MME/S-GW, while there may be tens of thousands of or even hundreds of thousands of HeNBs which are linked under one HeNB GW, and now the above-mentioned maximum values stipulated by the original protocol cannot by far meet the networking requirement. The typical situation is that, after introducing the HeNB GW, the number of the HeNBs hung under the HeNB GW is large, but the usable resources are limited, and the situation may happen that the TAC(8)/CSG(8) of a certain HeNB under the HeNB GW is not reported in the message to the MME. Because the paging message is paged according to the TAC/CSG, if the MME does not receive the message about the TAC(8)/CSG(8), it may think that there is no cell of which the TAC is 8 and the CSG is 8 under the HeNB GW, then the paging message used for the TAC as 8 and the CSG as 8 would not be issued to the HeNB GW, and the users in the cell will never receive the paging message.